Railway traffic controlling apparatus



F. w. PFLEGING RAILWAY TRAFFIC CONTROLLING APPARATUS July 4, 1944.

Filed May 2'7, 1945 2 Sheets-Sheet 1 AHW July 4, 1944. F. w. PFLEGING RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May 27, 1945 2 shee'ts- Sheet 2 Patented July 4, 1944 RAILWAY TRAFFIC CONTROLLING APPARATUS Frank W. Pfleging, deceased, late of -Omaha, Nebr., by Carrie E. Pfleging, administratrix, Omaha, Nebr., assigno'r to The Union Switch and Signal Company, Swissvale, Pa a corporation of Pennsylvania Application May 27, 1943,Seria1 No. 488,760 5 C laims (01. 246-33) This invention relates to railway tra-fiic controlling apparatus, and more particularly-to'-'ap-' paratus for governing traflic on a single track railway. J

Signal systems for single track railways ra-' lost when a track circuit becomes deenergized with the section unoccupied.

Accordingly, a feature of the invention-is the provision of improved railway trafiic controlling apparatus for governing traflic on a single track railway and wherewithrestrictive signal-indications are displayed inthe approach to a stop signal in such a mannerthat stopping distance forhighspeed traffic is provided.

Another feature of the invention is the provision of improved railway trafiic controlling apparatus for governing traffic on =a-single' traclr railway and wherewitn it is not possible fortwo a 015-, posing trains to leave adjacent sidings simultaneously and each train approach an intermediate signal displaying a-stopf indication without at: least one train receiving an approach'indication. 7

Again, a feature ofthe invention isthe provision of single track 1 railway traffic controlling apparatus incorporating novel means wherewith a loss of'directional control due to=a= track circuit circuit controlof each signal to include-a suffia cient number of track section's sothat -'-ior i'ellowing: moves. an approacli signalis displayed. a braking'distanceao-therear eta-stop signal. For opcsingamcves at a sldi'ng -location theline' c ircuit cont; 01s are overlapped so that each of two opposing trains approaching that siding is provided with an approach signal braking distance to the rear of the entrance'end of the siding for the particular train. For opposing movements between'adjacentsidingsthe controls of the opposing leaving signals are overlapped by the'control of a preselected one of these two signals extending one or more track section's beyond the leaving end of the remote siding'so that this pre selected signal displays an approach indication before the opposing train leaves the-remote siding. In this way two'opposing trains cannot leave these two sidings simultaneously under clear-signal indications and each advance toward-an intermediate signal at stop, the one train being provided with anapproach indication at its leaving signal. To avoid a loss of directional control in the event a track circuit for the section between opposing intermediate signals becomes deenergizedwith'the section unoccupied, the pickup circuit of the directional stick relay of a preselected one er these intermediate signals includesacontactof the controller of the opposing signal and closed only at the stop position of that signal and aback contact ofthe-directional relay for such opposing signal. Thus-if the track relayof this section becomes released with the section'unoccupied only the directional relay for the aforementioned opposing signal is picked up and the correspondingdirection of trafilc is establi'shed.

One form of apparatus embodying the invention will be described, and the novel features thereof pointed out in-claims.

In the accompanying drawings, Figs. 1a and 1b, when taken together with Fig. 1a placed at the left, are diagrammatic views showing one form of apparatus embodying the invention when used with a-single track railway signal system having staggered intermediate signals which are spaced braking distance apart. Itisto be understood that the invention is not limited to this one use and the present application serves to illustrate the many places Where apparatus embodying the invention will'be useful.

Referring to Figs. 1a and 1b, the diagram at the upper portion of the drawings designates a stretch of single track'railway including adja cent sidings IPS and ZPS, and which stretch is arranged by the usual insulated rail; joints with consecutive track sections designated IT to IIT, inclusive. These track sections are preselected as to their lengths to assure train-stopping distance with respect to wayside signalsassociated' therewith in a manner to appear hereinafter.

Each of the track sections is provided with a track circuit of the well-known form including a track relay responsive to occupied and unoccupied conditions of the respective section, each such track relay being conventionally indicated in the drawings by a dotted "line identified by the reference character Raplusia prefix corresponding to the reference character of the respective section.

Traffic through this stretch of railway from left to right, that is, eastbound trafiic, is governed by a first set of wayside signals 23, 4S, BS, 88 and HIS located at intervals through the stretch, and trafiic through the stretch from right to left, that is, westbound traffic, is governed by a second set of wayside signals IS, 3S15S, 1Sand HS, located at intervals through the stretch.

These signals may be of any one of the'several .gized to open front contact 20, the home signal arm of signal 38 gravitates to its horizontal position. The distant signal arm of signal 38 is operated to its lowered position by an operating circuit that includes front contact 2| of an associated control relay 3D and also front contact of control relay 3H,-and this signal gravitates to its horizontal position when this operating circuit is opened by either relay 3D or 3H being destandard types and two position lower quadrant semaphore home and distant signals are shown. A home signal is identified by a semaphore arm having-a square end and a distant signal by a semaphore arm having a fish-tail end. Each semaphore arm is gravity biased. to a raised or horizontal position, and is motor operated to a lowered position which is about 60 degrees below the horizontal. The horizontal position of a home signal arm is a stop signal indication, and the 69 degree position is a clear signal indication, and the horizontal position of a distant signal arm is an approach signal indication, and the 60 degree position is a clear signal indication. Three different indications, stop,- approach and clear, are effected for a signal by both a home signal and a distant signal being mounted on the same mast with the home signal above. For night indication, a home signal displays a red light at its horizontal position and a green light at its lowered position, and a distant signal displays a yellow light at its raised position and a green light at its lowered position. It is to be understoodthat the invention is not limited to lower quadrant semaphore signals and upper quadrant semaphore signals, searchlightor other forms of signals can be used. 1 v It should benoted at this point in the description that each signalv has a circuit controller operatively associated therewith and with semaphore signals each such circuit controller is operatively connected with the mechanism that actuates the semaphore arm and each controller actuates circuit contacts according to the position of the arm. In the drawings such controller contacts are shown in the usual conventional manner and are placed at positions remote from the respective signal in order to simplify the drawings, Each such controll er contact is identified by a reference character corresponding to the associated signal together with a distinctive numeral. Also, in many instances. in the drawings relay contacts are shown remote from the relay and each such relay contact is identified by the reference character of the respective relay together with a distinctive numeral.

The, operating circuit of each of the signals is controlled by a relay, the control relay for each home signal being given the reference character H plus a numeral corresponding to that for the respective'signal, and the control relay for each distant signal being given the reference char acter D plus a'numeral corresponding to the respectivesignal. 7 The-arrangement is such that when a control relay is energized -the operating circuit for the respective signal is closed to oper-.

ate the signal to its lowered position, and when the relay is e ne s t e. operating .circuittis the opposite signal 4S; and lamp of signal.

48 is lighted by an obvious circuit including backcontact 26 of relay 3H for signal 38. At the single location of signal 58, the lamp 2'! of signal 58. is lighted by a circuit including back contact '28 from a relay 5AE controlled in a manner to. appear hereinafter. Each signal control relay H and D is governe by a line circuit which in turn is controlledby the track relays and signals in advance of the signal controlled by the respective relay, such line circuit being extended a sufiicient number of .track sections in advance and the different controls overlapping in such a manner thatrestrictive s'ig-. nal indications are displayed in the approach of a stop signal for stopping distance for, high speed traffic. These line circuits will be more fully ex'-. plained when the operation of thev apparatus is described. v

The intermediate home signals BS and 18' are provided with directional. relays GSR and 118R, respectively, to permit following train movements throughthis stretch of track, each such directional relay being provided with a pick-up. and a stick circuit and these circuits being electricala ly interlocked so that directional control is..not lost if the track circuit for'the intervening section IT is deenergized for any. reason whilethe secs tion, is unoccupied, To be explicit,-the pick- 1m circuit of relay fisR'extends from, terminal..-'B through back contact 29 of trackyrelay ilTRiof section 1T, back contact 30- offthe other;,-direc.- tional relay ISR, controller contact 31 ,of signal 1S and closed only-at the raised ,position QfsignallS, controller contact 32 of signal ,BSand closed during a preselected interval while this signal is moving between its two positions and here shown as closed betweensubstantially 20 degrees and degrees of the movement, and winding of relay 6 8R to terminal; C. ,Relay GSR once picked up is retainedpenergized by. a stick circuit including back contact; 33 of control relay 6H for the associated.- signal-.65; and-front contact 34 orrelay. 6SR.', The'pick-up'circuit for directional relay .TSR. canbe traced from terminal B, through back contact .29 of .track relay 'ITR, controller contact 35 of signal IS and closed during a preselected movement of the signal between its two positions and shown as closed between 20 and 50 degrees of the movement of the signal, and winding of relay 'ISR to terminal C; and the stick circuit for relay 'ISR ineludes back contact 36 of control relay 1H and front contact 31 of relay 'ISR. It is to be seen from these circuits for the directional relays SSR and 'ISR that when an eastbound train enters section IT to shunt track relay 'ITR.v and deen-. ergize control 6H in a manner to later appear, to set signal 68 to stop, the directional relay BSR is picked up during the interval signal is. is gravitating to its raisedposition to close controller contact 32, providing the opposing signal is has previously been set to stop to close its controller contact 3|. Directional relay BSR when thus picked up is retained energized until such time as the control relay 61-1 is picked .up

to open back contact 33. When a westbound train enters section IT to shunt track relay ITR. to deenergize control relay 1H and set signal 1S to stop,. directional relay 'ISR is picked up during the movement of signal is to its raised position and its controller contact 35 is closed, and relay ISR once picked up is retained energized until such time as control relay 1H is reenergized to open back contact 36. It is to be observed that directional relay 'ISR is energized during the movement of signal IS to stop irrespective of the position of signal 68, whereas directional relay BSR is picked up during the movement of its signal. (is to stop only'if the opposing signal 'IS- has previously been set to stop. If now the track circuit for section 1T becomes deenergized to release track relay ITR at a time the section is unoccupied and both signals 6S and IS are clear, the directional relay 'ISR. has the preference and will pick up during the movement of signal is to its raised position, whereas relay GSR whose pick-up circuit includes controller contact 31 of signal is remains deenergized because by the time signal is reaches its raised position to close contact 3|, the circuit for relay GSR is opened at back contact 30 of relay 'ISR. Consequently, a westbound direction of traffic is established in the event of a failure of the track circuit for the section between the intermediate signals 65 and is when such failure occurs with the section unoccupied. That is to say, the westbound directional relay is given preference over the eastbound directional relay in the energizing of these relays when the associated track circuit becomes deenergized while the section is unoccupied. It is to be understood of course that the eastbound directional relay can be given preference over the westbound directional relay. f

In describing the operation of the apparatus, it is assumed at the start that the sections are all unoccupied and the signals and relays occupy their normal positions, that'is, the positions illustrated inthe drawings. Further assuming that with the signals spaced as shown in Figs. la and 1b, each track section IT, 2T, 3T, 4T, 5T, IT, 9T, 111T and HT is of a length sufficient for ample stopping distance for high speed traffic. Then assume that under such normal condition of the apparatus an eastbound train approaches siding IPS from the left and travels through the stretch to siding ZPS. As will shortly appear, this'eastbound train will have caused signal IS to be set to stop prior to the train entering section IT, and with signal causes signal 58 tobe set to display'an approach indications Thus asr-this eastbound train-5ap.- proaches thesiding .IPS, the westbound leaving signal IS is set to stop and anapproach indb V cation is displayed at both signals 3S1and'5S for any westbound train approaching the'siding IPS. a

When this eastbound train enters section IT; the track relay ITR. is shunted to openfront contact 4|] which is interposed in the line circuit of control relay 3H, and relay 3H isdeenergized to open frontcontact 20 and cause signal 3S.to be set to stop. Signal 38 on being set to stop moves controller contact 4| to an open position and the line circuit for relay 5D is opened :at. a second point and the. linecircuit for control relay IID is also opened, this latter relay becoming deenergized to open its front contact 44 and cause signal Us to display an approach indication. Consequently when this eastbound train Yapproaches siding IPS anapproach'signal is dis played at signal HS for any westbound train that might be about to leave siding -2PS. As

will appear more fully hereinafter, such extended control to provide a restrictive indication: at'the second siding in advance has the advantages that it is not :possible for twoopposing trainsto leave adjacent sidings simultaneously and each-train approach an intermediate signalat stopwithoutanapproach indication for at least one of the trains- Track sections 2T and 3T at siding IPS are next traveled in the order named by this eastbound train and track relays ZTR and 3TR-are shunted as the respective sections are occupied. The release oftrack relays 2TH and 3TR opens the line circuit for relays 3H and 3D at additional points and also the line'circuit for relays 2-H and 2D, the circuit for relay 2H including front contacts 45 and-46 of relays 2TB and 3TB, respectively, and the circuit for relay '2D-including' front contacts 41 and 5B of relays ZTR and 3TB;

V respectively. Thus relaysQI-I and 2D are dee'n ergized and signal 28 is set to stop behind the eastbound train.

This eastbound train upon moving away from siding IPS toward the next adjacent siding 2P3 enters section 4T shunting track relay 4'I'R which releases to open front contacts 48, 49 and '50 interposed in the line circuits for control relays II-I, 4H and 2H, respectively. The deenergizing of control relay 1H to open its front contactil sets the opposing westbound intermediate signal ISto stop and the deenergizing of control relay 4H to open its front contact 52 s'ets signjal4S to stop behind the train. Front contact 50 is'inter posed in the line circuits of both relays 2'Hand 2D so that signal 28 is retained at its stop position with the train in section 4T. The release of control relay 1H opens its front contact 53 which is interposed in the line circuit forrelay HH and that relay is deenergized causing signal HS at siding ZPS to' move to its stop position due to the openingof front contact 54' of relay HH. .Thus as the eastbound train moves away from. siding IPS, the opposing westbound signals 181 and HS are set to stoprto protect :the eastbound train against opposing .westbound train movements and signals 4S and 2S 'to the rear of'the train display stop to provide ample stopping'distance for any following train. Itis to be observed that with the leaving signal. HS set' to stop the two westbound signals (not shown) to the right of signal IIS are set'to display an approach indication in the same manner signals 3S and '58 are caused to display an approach indication when the leaving signal IS is set -to stop. ltois also to'be observed thatlrela ..'6AE whichiis interposed'in series in theline circuit for relaycl'II-I is ,deenergized. whenfltrackz relay lTRisshuntedzand relay GAE upon releasing to close its back contact 55 approach lights the lamp for the eastbound signal 68. Also, relay AE which is interposed inthe line circuit for relay 4H is now deenergized to close at its back contact 28 the circuit for lamp 2'! of signal 5S but the lighting of the lamp of signal BS is of no particular significance at this time.

Track sections 5T and BT are next occupied in the order named by the eastboundtrain and the respective track relays 5TB and BTR' are shunted to open the previously mentioned line circuits at additional points, but no new control is effected in advance of the train. When the rear of the train vacates section 4T, the track relay 4TB is reenergized to complete at its front contact 50 the line circuit for relay 2H, and the home signal arm of signal 28 is operated to a lowered position, but relay 2D remains deenergizeddue to itscircuit being held open atcontroller contact 56 of signal 45 and at; front contact 51 of relay 4H, and the distant signal arm of signalZS is not operated and signal 2S displays an approach indication.

-This eastbound train next passes signal 68 to enter section 1T and shunt track rela T'IRwhich releases to open front contacts 58, 59 and 60 and close back contact 29. The opening of front contact "58 opens the circuit for relay 1H at an additional point, the opening of front contact 59 deenergizes relay 6H to set signal 68 to stop, and the opening of front contact 60 controls the line circuit for relay H1 at an additional point, while theclosing of backcontact .29 bringsabout the picking up of directional relay GSR in the manner previously explained, relay 68R being p cked up because the opposing westbound signal -1S has previously been set to stop to close controller contact 3|. I

This train upon advancing into section 8T shunts track relay STR to open the line circuits for-relays 6H, 1 IH and MD at additional points. When the rear of the train vacates section 1T so that track relay 'ITR is reenergized, the line circuit for relay lHv is closed at front contact 60 of track relay 'ITR since front contact 6| of directional relay GSR. forms a shunt'path around front contact 62 of control relay 6H with the result that signal 4S is cleared for any following eastbound train that may wish to advancefrorn the siding IPS. I v 7 Occupancy of sections QT and IT by the eastbound train shunts track relays 9TB and IOTR, respectively, to open the line circuits for relays 6H, NH and HD at additional points; Also the circuit for control relay 8D is opened at front contact 63 of trackrelay 9TB and signal 86 is set to display an approach indication. When this train yacates section-l I071; the. apparatusis re;

stored to it's, normal-condition 'except'lforythe' fact .that signal HIS- displaysistop :and signal 83- displaysapproach because of the .traimoccup'ying the; track qcirc'uitv of section 1 IT, such ,con'- trol being effected in the same manner that. signal 25' is controlledrby the train: occupyingthesece tion2T., The operation of-theapparatus for-a westbound-train is similar to that fortan eastbound train movementand the. operation of the apparatus fora westboundtrain will be readily understood'by an inspection ofthe drawings, taken with the descriptionof the operation of the apparatus for the. eastbound train. However, it is to be noted that for a westbound train in'section HT at siding ZPSv no eastbound approach indication is effected for leavingxsignal 48 at siding IPS, it being s'ufficient to'extend'thecontrol of the one leaving signal I IS beyondithe next' adjacent siding. IPS only, .it being recalled that signal .I IS ismade .to display an approach indie cation gwhen an eastbound. train occupies .sec--} tions lT, 2T and 3T at-siding IPS.1 If an eastbound train is:in siding lPSand-a westbound train isin siding 2PS, and the two trainsmove out of ;the sidings to enter the sec-' tions QT and WT, respectively, simultaneously, both trains will not approach the intermediate signals is and ZS which display stop without one train having been given an approach indi cation, the. westbound train being given an ap-' proach; indication at signal US as .soon as the eastbound train entered section 3T.- Consequently,-whenr two trains simultaneously move away from thertwo sidings; the. westbound train will have stoppingv distance between. approachL-signal HS and the stop. signal 'lS, and the/east-v bound train, even if it has noadvance sight of signal 58 willhave the distance between signals Gsand IS as La stopping distance, it being-recalled that section T'I isv made long enough for stoppingdistance for high speed traffic; If an eastbound train and a westbound train approach a passing siding, such as siding IPS, for example, the-westbound trainreceives an approach indication. at Jsignal 5S beforereceiving a stop signal. at signal 3S, and the eastbound "trainrecives an approach signal at a signal next to the'left of signal 23 and which signal is con trolled in a manner similar to signal 88, before such train reaches the stop signal 2S, and cone seq'uently each of the trainsis"provided" with ample stopping "distance before encountering a,- stop signal at the respective entrance end of the siding. 7 j It is'to be seen'from 'the'foregoing description that apparatus has been providedfor controlling wayside signals wherewith ample train stopping distance for high train speeds is'provided for both followingv and approaching train movements and it is not possible "for opposing-trains to leave adjacent sidingssimultane ously and each train approaclran intermediate signal at stop without at least one of the, tr'ains having previously receivedan approach indication. Also a; loss, of

directional control duetothe failure of a track circuit when the. stretch is unoccupied is avoided. Although herein has been shown and described but one form of railway traffic controlling apparatus embodying the invention, .itis underistood that various changes and modifications sniiiit, ildl QQPQ i the-i ventions.

Having thus described the invention, what'is claimed is:

1, In combination with a. stretch of railway, track formed with consecutive track circuited sections and extending from a section on one side of a first siding past that first siding to a second siding, a first set of signals spaced at intervals to govern trafiic in one direction through the stretch and including a first leavingsignal at the first siding governing trafiic toward the see nd siding and a second set of signals spaced at intervals to govern traific in the other direction through the stretch and including a second leaving signal at the second siding governing traffic toward the first siding; control relay means for each of said leaving signals, a first line circuit means controlled by the track circuit of each section between said sidings to govern the control relay means for said first leaving signal to cause operation of said first leaving signal to a stop position when any one of such track sections between the sidings is occupied by a train moving toward said first siding, and a second line circuit means controlled by the track circuit of each section of said stretch to govern the control relay means for said second leaving signal to cause operation of said second leaving signal to an approach position when either said section on one side of said first siding or a section adjacent said first siding is occupied by a train moving toward said second siding and to a stop position when any one of the sections between said sidings is occupied by a train moving toward said second siding.

2. In combination with a stretch of railway track formed with consecutive track circuited sections and provided with a first set of signals spaced at intervals to govern trafiic in one direction and a second set of signals spaced at intervals to govern trafiic in the other direction, a pair of intermediate signals one of which is included in said first set and the other of which is included in said second set and said intermediate signals located at opposite ends of an intermediate one of said sections, a directional stick relay for each of said intermediate signals, twocontrollers one operatively associated with each of said intermediate signals; a pick-up circuit of a selected one of said directional relays and having interposed therein a contact of the controller of the associated signal and closed for a preselected interval as that signal is moved from its clear to its stop position, a contact of the controller of the other intermediate signal and closed only at the stop position of that signal anjintermediate one-of said sections, a directional r'elayior. eacnofrsaid intermediate. signals, two.;controllers one operatively connected to one of ;the intermediate signals and the other operatively connected to the other intermediate signal; a pick-up circuit for the directional relay ofsaidxone signal serially including .a contact of. each of '.said;;controllers to energize that direc.-.- tional relay when said; one signalis beingset to stop only if said other intermediate signal has previously been set to stop, and a pick-up circuit for the directional relay of said other signal including a contact of the associated controller to energize that directional relay when said other signal is being set to stop irrespective of the position of said one intermediate signal, whereby loss of directional control due to a failure of the track circuit for said intermediate section is avoided.

4. In combination with a stretch of railway track formed with consecutive track circuited sections and provided with a first set of signals spaced at intervals to govern traffic in one direction and a second set of signals spaced at intervals to govern traffic in the other direction and each of which signals is governed by a control relay energized through a line circuit controlled by the track circuits of selected sections in advance of the respective signal, a pair of intermediate signals one of which is included in said first set and the other of which is included in said second set and said intermediate signals located at opposite ends of an intermediate one of said sections, a directional stick relay for each of said intermediate signals, two controllers one operatively connected to one of said intermediate signals and the other operatively connected to the other intermediate signal; a pickup circuit for the directional relay for said one and a back contact of the other directional relay; and a pick-up circuit for said other directional relay and having interposed therein a contact of the controller of the associated signal and closed for a preselected interval as that signal is moved from its clear to its stop position, whereby only said other directional relay is energized when the track circuit of said intermediate section becomes deenergized with both said intermediate signals at clear.

3. In combination with a stretch of railway track formed with consecutive track circuited sections and provided with a first set of signals spaced at intervals to govern traffic in one direction and a second set of signals spaced at intervals to govern trafiic in the other direction, a pair of intermediate signals one of which is included in said first set and the other of which is included in said second set and said intermediate signals located at opposite ends of intermediate signal and including a back contact of the track relay for said intermediate section, a contact of said one controller closed when said one signal is being set to stop, a contact of said other controller closed only when said other signal is at stop and a back contact of the directional relay for said other signal to energize the directional relay for said one signal when that signal is being set to stop only if said other signal has previously been set to stop; a pickup circuit of the directional relay for said other signal and including a back contact of the track relay for said intermediate section and a contact of said other controller to energize the last mentioned directional relay when said other signal is being set to stop, and each of said directional relays provided with a contact to control the line circuit of at least one signal of the associated set of signals.

5. In combination, a stretch of single track extending between two sidings and having formed therein a track section intermediate the sidings and which section is provided with a track circuit including a track relay, a first and a second signal located at opposite ends of said section to govern trafiic in opposite directions, a line circuit for each of said signals to govern the respective signal to its clear position when the portion of said stretch in advance of that signal is unoccupied and each such line circuit including a front contact of said track relay, a first and a second directional stick relay for said first and second signals respectively, a first and a second controller operatively connected to said first and second signals respectively; a pick-up circuit for said first directional relay and including in series a back contact of said track relay, a back contact of said second directional relay, a contact of said second controller and closed only when said second signal is at stop, and a contact of said first controller and closed for a preselected portion of the movement of said first signal from its clear to its stop position; a pickup circuit for said second directional relay and including in series a back contact of said track relay and a contact of said second controller closed for a preselected portion of the movement of said second signal from its clear toits stop position, and means governed by each directional relay when picked up to control the line circuit for the associated signal. 7 Y 4 CARRIE E. PFLEGING, Administratria: of the Estate of Frank W. Pfleging, Deceased. 

